Insulating cellvlosic mebibm



Nov 2, 1937.r F. w. HoHsTETTr-:R 2,097,694

- v INSULATING CELLULOSIC MEDIUM Filed Nov. 15, 1934 k2 sheets-smet 1 'lll/lllllllllllllllllllllll,lll/I2 'hva u 'In 0 .Jig 5.

Nov. 2, 1937.

INSULATING CELLULOSIC MEDIUM Fild NOV. l5, 1934 2 Sheets-Sheet 2 gwgegam @um Y! Y F. w. HocHlsTET'l-R l 2,097,694 A Patented Nov. 2, 1 937 msnm'rmc cELLULosic Mannini y Frederick W.'4 Hochstetter, Pittsburgh, Application November 15,

1934, Serial No. '253,206

' 15 Claims. (Cl. 154-28) My present invention relates to insulating material for heat, cold, and electricity and more specifically to such almaterial which is of a combined cellulosic and carbonaceous nature.

There are on the market today a products of a porous and inflammable.

number of cellulosic nature whichare light, These products, as

produced, have some value in connection with insulating against heat and cold trical insulation. Such products such nature that they glow,

but not for elecare, however, of

ignite, or burn when subjected to flame or combustion conditions and do not have as good insulating properties as they should or could have were they specifically treated 15. therefor. The extent of insulating ability which these materials possess uses and this, together volved, has very much application.

with the limited is insufiicient for many fire hazards in their industrial .I have found that by treating such mediums, as will be hereinafter set forth, I can endow them with such insulating eiect new materials and at the properties that theyare in same time I can renderl them very resistant, and such accordingly 'N constitutes one of ventlon.

the objects of the present in- Another object of my invention is to produce from known fabricated mediums of a cellulosic nature afsingle ply or laminated medium which has excellent insulating characteristics against heat and cold and the dielectric characteristics of which are such that they are excellent insulators for electrical purposes.,

VA further object of my invention resides in pro- '35 ducing an insulating medium derived from cellulose, ligno-cellulose, woody fibres and allied products or derivatives of cellulose which is capable of being laminated into various forms such that exceptionally good insulating properties are secured 4o for heat, cold, and electricity'to meet various con- Iditions of usage.

More specically, an object of my invention is to carbonize or char either or both surfaces of a 'dellulosic medium, with or without otherwise treating the medium,

to provide an insulating material which can be used as a singleplayer or in any combination as a laminated medium'. 1

Other and further objects and advantages will be understood by those skilled inthis art or will be apparent or pointed out hereinafter.

In the accompanying drawings, I have illustrated a-number of invention and insuch drawings:

embodiments ,of the present f Figure 1 represents in perspective a portion of 65 cellulosic medium -carbonized on one side;

which may be Fig. 2 is the same as Fig. 1, except that the cellulosic material is carbonized on both sides;

Fig. 3 is a view of two of the portions of Fig. l assembled with carbonized faces abutting;

Fig. 4 represents another form of the invention 5 faces of the upper and lower cellulosic layers contiguous to the carbonized surfaces are corrugated; 15

Fig. 7 is the same as Fig. 3, except an insert of insulation-enhancing material such as aluminum foil is Vplaced between the carbonized surfaces;

Fig. 8 is the same as Fig. 4, except that two insulation-enhancing inserts as per Fig. 'l have been 20 placed between the pairs of carbonized surfaces;

Fig. 9 is the same as Fig. '1, except that betweenl one carbonized surface and the insulation-enhancing insert a separate corrugated insert has been added;

Fig. 10 is the same as Fig. 7, except that a layer of insulation-enhancing chemical such as casein has been inserted between the carbonized surfaces;

Fig. 1l illustrates a modification of Fig. 1 where- 30 in the carbonized surface does not extend over the entire cellulosic medium and where the carbonization is effected according to a predetermined design;

Fig. 12 illustrates another modification of Fig. 1 3i wherein the carbonized surface is countersunk in the medium and wherein an uncarbonlzed border is left around the medium which may be coated with a suitable adhesive material;

Fig. 13 is a section across Fig. 12;

Fig. 14 represents two mediums like Fig. 12 laminated in a manner analogous to Fig. 3; and

Fig. 15 is another modication of Fig. 1 wherein the surface carbonization is in the form of bars or bands.

Since all of the various modifications of the present invention are essentially built up from'or derived from the fundamental section shown in Fig. l, it will be only necessary to describe in detail the invention as shown in Fig. 1. As already stated the portion I0 is composed of fibrous material which is preferably cellulose, lignecellulose, woody fibre or a, .cellulosic derivative in light, porous condition or which more dense, if pre- 55 may be compressed or made perl se is well known in relatively porous sheets now produced commercially in large quantities. I may or may not, and this is optional, otherwise treat such material as by spraying, dipping or any4 other known way, with any well-known heat resisting compound of which there are many on the market. Chlorinated naphthalene or 4other non-aqueous comon the market any suitable or-proper one may be selected for the particular product involved.

jecting it to a required heat for a. required length of time, depending, 'of course, upon the particular material. Where the medium is still wet from formation, or where it is wet due to saturation with heat-resisting compound, I suitably The medium Figure 1 carbonizing both surfaces of the cellulosic mate-k aoe'sgeea without additional inserts', the media of Figs. Fig. 3, for example, represents two media like Figure 11 assembled with their carbonized surfaces in contact. Like Figs. l and ,2, however, suchform also provides alternate layers of cellulosic and carbonaceous material.

It will be clear upon inspection that Fig. 4 represents a further laminated eiect as a result of placing two media like Fig. 1 together, carbonized surfaces not abutting, and adding a plain ele-` ment or medium thereto.

air 'columns or low circulation spaces may be open-ended to a1- of air or may be sealed' at the ends according to circumstances.

The modification shown in Fig. '7 involves the rtwo such inserts 'I6 have been made pairs of carbon'ized surfaces il, ication of Fig. 4, In Fig. 9, I have combined the -use of a'metal r metal foil corrugated fibrous insert I5,

of the invention which finds use in may be according to Fig. 6 in their treatment.

caused to more rmly adhere, it necessary, by utilizing a heat-proof adhesive or binder such as a special coating, adhesive or any like or or varnish may be applied i cellulosic surfaces, which may bound, if desired, as by wiring,

to the necessary also be otherwise 'I'he air spaces formed stapling, etc.

surfaces impervious Again, to

a single layer or a pl render exposed cellulosic to moisture or immune to demedium whether it be ied medium so as to maintain the efficiency and effectiveness thereof for prolonged perio ment By surfaces and leaving a of uncarboniz'ed I fa the laminations since i sulating adhesive can bonized surfaces and o cured. I

ForV example,

is like a checkerboar or border I8 to which a Preferably, the

' low the margin or such mediums in t area l1 is c are Fig. 3 the plied medium spacesNbetween providing an exc The ratio bonized area may be dium.

border laminated in the manner of 'Letters patent is:

ds without requiring replacelimiting the carbonized area of the cellulosic portion or portions therecilitate .the adherence of n such case' a suitable inbe applied to the -uncarther advantages are ser Fig. 11 thecarbonized area l1 d with an untreated margin dhesive can be applied.

ountersunk a little bel1. Thus when two will provide alternate carbcnized and uncarbonized areas with air the opposed eptionally good insulating ecarbonized areas thus of uncarbonized area to carsuitably adjusted during formation so that the required or proper insulating effect is sec ured. This form of carbonization may be carried out by forming a wire stencil which is electrically drying tunnel or hot .stencil is broughtfinto dium whenidesire lowering the' stenc ing a Apressure a stencil or severa .that the medium that they act sync treatr both sides at InFigs. 12 an central portion carbonized border cated adhesive ,'countersunk (as Two such medium vide carbonized between. -The securing together more when desirable.

-In Fig.`15, the car v form of'bands,

portions 24 for uniting by Cil paSSeS heated and installed in the 'oven in such manner that theN contact with the med by a .suitable mechanism for il onto the material and exert- The carbonized area is' thus simultaneously compressed somewhat and this gives the? coun l stencils may be located so between hronously as a clampand thus If desired them and so Athe same time.. d 13, IA have carbonized the whole I9 ofthe medium'leaving an unareas with uncarbonized areas firmly of the laminae url margin on which is indi- UIhis carb'onized area may be or not, as preferred.

s as assembled in Fig. 14 "proan air space 22 therefacilitate the boni-Zed yareas 23 `are in the stripes or bars leaving untreated the sources g toFig. to give Lthe desired extent only adhesive. This form readily produced by approof heat duringcar.

1, e. g., by spacing Still other variations and modifications are possible as wil disclosure and only to the' foregoing prehended within long as they make use of enumerated.

It is thus appare I do notv novel insulating material layer thereof comprises rial either or bonized to a su'i affecting the poros Amaterial as a lowering the t Such material whole, and without beunderstood from the above i-l'ritend to limit myself as other forms are comthe spirit-1 of the invention kso the principles Iherein nt that -I have produced a which fto a single light -cellulosic mateoth surfaces of which are car- A table depth without adversely Q ity and the lightness Vof the" appreciably ensile strength. of suchv material.

may be plie d or laminated inany.

tioning systems, airplane fuselage lining,

` a good insulator all the varying conditions which might be encountered in use. I have found for example in one or other of the'various forms disclosed, such insulating material is exceptionally advantageous, especially when heat-resistant, for 'use in heating or refrigerating systems, air condihouse wall l1ers, and electrical installations as well as many other commercial applications where a light moreor less porous material is desired and where frequently space and/or weight limitatiOns'preVent the use of other/ or heavier insulating materials. In using the term cellulosicf in the claims I intend it in its, broadest or most general sense as including cellulose. ligno-cellulose, and cellulosic derivatives,-com pounds, etc., and including woody fibres.

What I claim as neWand desire to secure by `1. A cellulosic medium characterized by being for heat, cold, and electricity comprising 'a body of cellulosic material provided with one or more surface-carbonized portions.

. 2. A cellulo'sic medium characterized by being heat-resistant and by good insulator for heat, cold, and electricity comrial with either or both prising a body of heat-resistant cellulosic mateto carbonized condition.

of its surfacessrconverted" properties rendering it a 3. A laminated cellulosic medium characterized by its good insulating properties for heat,`c'old, and electricity comprising alternate portions of uncarbonized cellulosi material and carbonized -material.

- heat-resistant cellulosic 4. A laminated cellulosic medium characterized by being heat-resistant and by its good insulating properties forheat, cold, and electricity comprising a series Aof laminaticns each having a body and one or two carbonized surfaces alternate`portions of cellulosic material and carbonized material make up the laminated medium.

5. A method of making a cellulosic medium for insulating purposes comprising treating ce1- lulosic material to make. .it .hydrating both surfacesthereof by subjecting the same to suicient heat for a suicient time.

`6. A method comprising producing a plurality of media in accordance with claim 5 and then plying'the same to form a'laminated medium vhaving alternate cellulosic and carbonaceous portions.`

7. A method of making wheat-resistant insu-.

lating cellulosic medium of the kind described any suitable' agent comprising treating vbonized and the remainder of thesurface uncarbonized.

of carbonized and uncarbonized cellulosic mate- 19; -An insulating medium of cellulosic character provided with countersunk carbonized areas.`

10. A'laminated insulatingrmedium made up so arranged that, in eiect,

rial, the laminae of whichare adhesive1y secured V such medium.

together by a suitable insulating, heat-resistant coating.

11. A method of making an insulating cellu- 13. -As a new article of manufacture, a nonhomogeneous insulating medium composed of a brous base thereof charred under controlled conditions.

from' the group: cellulose, ligno-cellulose, woody l fibres, cellulosic derivatives.` '-A 15. As a,new article of manufacture, an insulating lmedium composed of cellulosic material in sheet or strip-like form, the surface of which having predetermined portions llil 

